Stratospheric Gravity Waves as a Proxy for Hurricane Intensification: A Case Study of Weather Research and Forecast Simulation for Hurricane Joaquin

Abstract

Tropical cyclones (TCs) are among the most destructive natural weather phenomena and can cause extensive damage to coastal countries and regions. Close monitoring and accurate forecasts of the tracks and intensity of TCs are needed to reduce human and financial losses.Tropical cyclones are powered by latent heating, mainly from strong updrafts in the eyewall (Charney & Eliassen, 1964;Emanuel, 1986;Kuo, 1965), and latent heat release in the storm is responsible for the dynamical structure and intensity change of the storm (Braun, 2002;Cecil & Zipser, 1999). Latent heat release is also involved in generating stratospheric gravity waves (GWs) (

Effects of Stratospheric Gravity Waves on Convection in the Troposphere During Typhoon Lekima 2019

“…The absolute errors of the LR and LSTM models are 0.067 (0.087) and 0.135 (0.045), respectively, when the ASGWs-A is smaller (larger) than 0.5, which shows that the relationship between the ASGWs-A and CI-85 is primarily linearly (nonlinear) when the SGWs are weak (strong); therefore, the role of nonlinear interaction cannot be ignored, especially for strong SGWs. The results from the models are thus sufficiently accurate for the SGWs to be used as a proxy for the CI, consistent with Wu et al (2021).…”

“…Wu et al. (2021) argued that the gravity waves (like those in area B) may be used as a proxy for typhoon intensity, and we raise the question as to whether the SGWs‐A with similar wave parameters to the SGWs‐B influence the intensity of convection (CI) in area A.…”

“…Wang et al (2021Wang et al ( , 2022 have clarified that the waves in area B (SGWs-B) are generated by Typhoon Lekima. The relationship between the intensity of SGWs and the typhoon has been studied by Wu et al (2021), who found that the SGWs change before changes occur in the intensity of the typhoon. Therefore, SGWs may be used as a proxy for typhoon intensity.…”

“…However, Wu et al. (2021) also argued that there are substantial complexities in the physical relations between latent heat release, hurricane intensity, and GW activity being involved and it still remains unclear whether and how do the SGWs has a feedback effect on the source of the waves rather than that the only statistics lag relationship between the intensity of the SGWs and TCs.…”

“…When latent heat release increases, GWs are triggered and propagate fast in the vertical direction. They can be observed in the stratosphere even before the hurricane intensity itself increases (Wu et al., 2021). However, Wu et al.…”